This is the website/blog of Philosopher Stephen Law. Stephen is Provost of Centre for Inquiry UK, Reader in philosophy at Heythrop College, University of London, and editor of the Royal Institute of Philosophy journal THINK. He has published several books (see sidebar). His other blog is THE OUTER LIMITS: http://www.centerforinquiry.net/blogs/blibnblob
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Sunday, August 3, 2008

Sye on "proof" - a further consequence

1. The existence of objective laws of logic necessarily requires the existence of the Christian God2. Objective laws of logic existTherefore, God exists

Now, if we want to show this is not a "proof", as Sye defines "proof", we must either show the argument is not valid, or we must show a premise is false.

But we do accept that it's valid (cos it is), so we have to show that one of the premises are false. If we accept 2 (which, for argument, I do), we have to show 1 is false.

So, on Sye's definition of "proof", if we wish to demonstrate he does not have a "proof", the onus is on us to disprove 1. i.e. by coming up with an alternative, non-Christian account of objective laws of logic!

See? there is a kind of twisted logic to this.

Of course, on a standard understanding of "proof", to show it's not a proof, all we have to do is show his argument contains an unargued for and contentious premise, which it obviously does.

Of course, Sye has misunderstood what a proof is (as I am happy to explain further once he defines "presupposition"), but, to be fair to Sye, it's kind of an understandable misunderstanding.

After all, validity and true premises are things we want to see in a deductive argument, aren't they? Sye just overlooks that, for the argument to justify and provide rational support to its conclusion, something more is required...

So, on reflection, I can now make more sense of where Sye's coming from (though I doubt he'll accept this diagnosis). Previously I had suspected he was just nuts....

40 comments:

So, this is just another case of 'reversal of the burden of proof' that Sye's trying to pull on us.

We just have to state:You say "The existence of objective laws of logic necessarily requires the existence of the Christian God"

Prove this.

Actually previously I was thinking a malicious leprechaun introduced Sye's kind of logic into the world. I have proof of that:- "Laws of your kind of logic necessarily requires the existance of a malicious leprechaun"- you use your kind of logicI conclude from this statement that leprechauns exist.

In a further attempt to get at what Sye meant when he rejected the statement starting "If God exists..." it occurred to me that he might be saying, amongst other things, that it is not valid to use "God" as part of any conditional. A sort of variant of the "you can't say anything about God" type of theology.

For a while all this has seemed strangely familiar. Then I realised I think I might have debated Sye back in 2006 when he was called 'Canuckfish'. Though I suppose it could have been somebody following the same flowchart.

If anybody is interested in seeing how his argument has remained unchanged all this time, you can have a look here.

Sye won't be able to explain what he means by "presupposition" without dropping his whole argument. His whole whole thesis rests on a confusion of premises with conclusions and the assumption that others do the same.

This is "presuppositional apologetics" after all. Sye's premise is his conclusion: that God exists. All his "arguments" lead back to this and the assertion that others do the same. "My presupposition is my conclusion. Therefore other people's presuppositions must be their conclusions. Therefore an atheist, who concludes that God does not exist, must be pre-supposing that God does not exist." If Sye admits that someone can look at something an conclude something else, if he admits that some people can revise their prejudices his whole argument falls.

"Valid" refers to an argument where if the premises are true then the conclusion cannot be denied whether or not the premises are in fact true. So it refers to the logical form of the argument rather than the content. "If X then Y, X, therefore Y". Is valid because the form of the argument is correct. (We have no idea whether either premise is true as we have no idea what X and Y mean.)

The term "Sound" is usually used for a valid argument that also has true premises (a thing Sye confuses with "proof").

Remembering it as best I can:"If anybody knows Owl will know, or my names not Winnie the Pooh. Which it is, so there you are."Is perfectly valid (if X then Y, X, therefore Y). It is unsound because the conditional given by Winnie the Pooh is false.

The argument referred to by Stephen is much the same as Winnie the Pooh's. The second premise is true (or we accept it as true), the deduction is valid but the conditional is bollocks. As Stephen has pointed out, with far more patience than I would have shown, it depends on a basic confusion of metaphysics and epistemology. I am pretty sure Sye does not understand the difference but chooses to ignore it rather than learn.

anticant - I do think objective laws of logic exist, in the sense that e.g. its objectively true (not just true because we say it is) that certain forms of inference are truth preserving and others not.

Of course, that's not yet to commit myself to any sort of Platonic heaven logical laws, or anything like that, which is I guess what would bother you?

Well, looking at Psi's page, if you read very, very closely you can see Canuck at one point signed his post as, "Sye". I think that's pretty conclusive, because the name isn't particularly common, to my knowledge.

psiomniac said: "For a while all this has seemed strangely familiar. Then I realised I think I might have debated Sye back in 2006 when he was called 'Canuckfish'. Though I suppose it could have been somebody following the same flowchart."

Hey Psi! Sye here. Yes that was indeed me, good to meet up with you again!. I'd forgotten all about that profile, thanks for the link!

"You use universal, abstract, invariant laws every day. How do you account for them in a random, chance, material universe?"

Whereas new Sye says:

"It has never been my argument that all atheists are crude reductive materialists, as you have accused me of suggesting, simply that atheists cannot account for universal, abstract, invariant entities."

Not sure how to square these two remarks as they do seem to contradict each other. Could certainly use some explaining....

Psi's response cold easily have been that he does not believe that the world is solely material in nature (which he did not by the way), at which point the debate would have continued. I was just repeating what I hear from a lot of (read most) atheists I engage.

Can I, as an atheïst not account for universal, abstract, invariant entities?As they are abstract, they are the opposite of concrete, and thus part of the mental models we humans use.So, the answer is: we, humans, invented them.Of course, depending on the meaning of 'universal' and 'invariant', they might not even exist, as we humans live i na very small part of a very big universe.

Part of the problem in this discussion is, I think, semantics treated as metaphysics.

Sye's question "how do you account for the existence of abstract entities in your worldview is a good example.

We say, for example, "laws of logic exist". This wording implies, wrongly I think, that laws of logic somehow exist in much the way that physical objects exist (or, at least, that they exist in some analogous way).

But, of course, that idea seems pretty silly (far-fetched Platonic realms and all). And also wrongly implies that they could cease to exist (what if the laws of logic were wiped from the Platonic mainframe---magically 2+2 doesn't equal 4 anymore).

Instead, I think its more accurate to say something like "laws of logic are necessarily true statements".

More specifically, things like "it is necessarily true that internally contradictory statements must be false" and the like.

In other words, what we call laws of logic and logical truths are not objects which exist in some way analogous to the way a stone exists. They are simply propositions of a particular sort---ones which are noncontigent---can under no circumstances be false.

Which is, of course, why its silly to say these statements would cease to be true if God didn't exist. The truth of these statements is not contingent on any other thing existing or being true.

They don't need a "basis". They are themselves bedrock truths. There is not a more fundamental fact which they require as an explanatory basis. Which is, of course, why its impossible (and nutty) to "account for logic" in terms of something else (dieties or platonic realms or what have you). There is no more basic truth in terms of which one must account for logical truths because when you get to logical truths you have arrived at a set of basic truths---explanatory bedrock.

David,you said (of the laws of logic):"They are simply propositions of a particular sort---ones which are noncontigent---can under no circumstances be false."

I take your statement to say that laws of logic exist absolutely [noncontingent]

But they are contingent. They're contingent upon objects and a method of resolution. The arbitrary symblolism in a law of logic does not stand alone. That "A" cannot be "-A" at the same time is meaningless until applied to the world (which of course is what the idea was derived from). In order for it to be noncontingent it must have an independent existance, which nothing does. The truth of a logical proposition is relative to a system of proof.

This is why I've been pushing Sye that truth is systemic. Because Sye has been unable to prove otherwise, he simply says, "the laws of logic are absolute in the mind of God". In which case his arguement becomes:1.) God exists.

Thanks, Stephen and everyone, for a most interesting discussion. Yes, I am relieved that you [S] don’t believe the rules [which I prefer to “laws”] of logic, mathematics, and other mental working tools are Platonic Archetypes floating up there in the ether with or without Sye’s God.

Surely, what logic is essentially about is consistency in argument, because inconsistent arguments are useless and don’t help us to understand any better. As David says, “part of the problem in this discussion is, I think, semantics treated as metaphysics”. I agree. Maybe the Logical Positivists’ insistence on using precise language and being clear as to its meaning before going on to the next step wasn’t quite so arid and sterile as it’s now fashionable to assume?

And it isn’t a matter of “winning”, as both Sye and some of his critics seem to think. It’s about clarifying our own thinking, and our reasons for it. Regardless of whether or not Sye shifts his blinkered position [I don’t think he will], I for one am grateful to him for being such a useful stalking horse!

Hey Psi! Sye here. Yes that was indeed me, good to meet up with you again!. I'd forgotten all about that profile, thanks for the link!Hi Sye!

Psi's response cold easily have been that he does not believe that the world is solely material in nature (which he did not by the way)But I don't think you could fairly conclude from my dialogue with you that I am a reductive materialist, and in fact I picked you up on exactly the same point about randomness and chance that, two years later, have been mentioned on these threads.

So why not engage with some of the arguments about the ontological status of the rules of logic? And why not respond to the fundamental criticisms raised here, of your notion of the 'impossibility of the contrary'? Then perhaps you could say that after two years, you had actually made progress, even if you didn't change your overall conclusion.

”Of course, on a standard understanding of "proof", to show it's not a proof, all we have to do is show his argument contains an unargued for and contentious premise, which it obviously does.”

No, I argue for that premise by saying that the contrary is impossible, or the contrary leads to absurdity.

”Of course, Sye has misunderstood what a proof is (as I am happy to explain further once he defines "presupposition"), but, to be fair to Sye, it's kind of an understandable misunderstanding.”

Actually, I asked you to give me an example of a proof that does not contain any presuppositions. By presuppositon, I am happy to take the definition from this online philosphical dictionary: http://www.philosophypages.com/dy/p7.htm ”A presupposition is a necessary condition for either the truth or the falsity of the statement that presupposes it. Thus, for example, "My grand-daughter is a smart baby"—whether or not she exhibits intelligent behavior—presupposes that I do, in fact, have at least one female grand-child.”

I'd like to see ONE proof without previously assumed necessary conditions.

”So, on reflection, I can now make more sense of where Sye's coming from (though I doubt he'll accept this diagnosis). Previously I had suspected he was just nuts....”

I accept the diagnosis that I am not nuts :-D Still though, you can’t even justify THAT diagnosis, absent an absolute standard of sanity.

Before I end this post though, I want to address the notion that Stephen has answered my question as to how universal, abstract, invariant entities such as the laws of logic makes sense in any atheistic worldview.

I’ll take them one at a time: Universal entities: How can an atheist know anything to exist universally, without universal knowledge? If you have seen where Stephen has answered this, please point it out because I haven’t seen it.

Next, abstract entities. Sure, Stephen has listed a few atheistic worldviews that claim that abstract entities exist, but he has not told us how these entities make sense in any of those worldviews. Note too, that Stephen has not told us what his particular view or account of abstract entities is, why, I’ll leave that up to you all to decide.

Thirdly, invariant entities. How has Stephen explained how invariant entities can exist in his, or ANY atheistic worldview? How does he know that something has not changed or that it will not change? If you have seen where he has explained this, please let me know, because I haven’t seen it.

Lastly I addressed the problem of induction. I want to know on what basis Stephen assumes that nature is uniform. I have not seen any answer to this question, if any of you have, please point it out.

I'd also really like to know why, according to Stephen’s worldview, people should be logical, or if they should be, but I'll wait till he addresses the above comments (if he does that is).

So your saying that "grand-daughter" is presupposed. But, one can prove that they have a grand-daughter.

I could say, "my neighbor Chris has brown hair". By the definition you use, whether or not Chris has brown hair, the statement presupposes that I have a neighbor Chris.

But you see Sye, I can prove that I have a neighbor Chris. I can show you a picture, give you his and my address, I can buy you a plane ticket to come see him.

So can you show me proof of God in this way?

This is where you say, "the absolute laws of logic are proof." But this would be like me saying, "Chris's brown hair is proof that he's my neighbor." But I haven't even given proof that his hair actually "IS" brown aside from my assertion of it.

I take your statement to say that laws of logic exist absolutely [noncontingent]

I had two points:

1. that "exists" is the wrong word.

2. that logical truths are noncontingent true propositions.

But they are contingent.

They are not contingent. The proposition "internally contradictory statements are never true" is one which is never, under any circumstances, wrong. That's what I mean by noncontingent (or necessarily true).

In order for it to be noncontingent it must have an independent existance, which nothing does.

Again, this is precisely the way of viewing logical truths (as "objects" or "things" of some sort) which I, in point 1 above, am explicitly disagreeing with.

Logical truths are not objects.

They are necesssarily true propositions.

The truth of a logical proposition is relative to a system of proof.

The statement "internally contradictory statements are not true" cannot, under any circumstances, be false.

So we are back here again. OK, let's go round again. Only this time even more slowly and carefully.

On your website, you present this argument:

(1) The existence of laws of logic nec. requires the existence of the Christian God(2) The laws of logic existTherefore: the Christian God exists.

You call this a "proof". You have also said the argument on your website establishes, as it stands, the above conclusion beyond reasonable doubt, right?

Now we ask why we should accept premise (1). You say there is also an argument for (1) on your website. We look. We can't find it. You say it's behind the "continue" button. We still cannot find it - all we can find is the *assertion* that the contrary of (1) is impossible, but no *argument* that the contrary of (1) is impossible.

So, some questions:

(i) It is an argument, in the sense of premises and conclusion, that you supply to support (1), correct?(ii) This argument does lie on the page behind the "continue" button, correct?(iii) This argument does establish the truth of premise (1) beyond reasonable doubt, correct?(iv) In which case, can you help us by setting out the argument in question with numbered premises and conclusion? Like so:

Sye, you seem to be missing the point. Irrelevant of whether Stephen or any other atheist can answer your questions, your "proof" has been demonstrated to be not in fact a proof at all. If you would at least concede that much, you would win the respect of everybody else posting here and demonstrate that you were arguing in good faith. It would then also make it possible to have a discussion with you as a person, rather than have to watch you reading from your script.

A presupposition is a necessary condition for either the truth or the falsity of the statement that presupposes it. Thus, for example, "My grand-daughter is a smart baby"—whether or not she exhibits intelligent behavior—presupposes that I do, in fact, have at least one female grand-child.”

Ok Sye, lets run on that basis. “My grand-daughter is a smart baby” presupposes:1. I have at least one female grandchild2. That grandchild is a baby3. That grandchild is smart

First note that anything outside the set of necessary conditions is not a pre-supposition . Thus:1. Led Zeppelin are a great rock band2. Beer is bitter3. Koppites are gobshitesAre not pre-suppositions of “my grand-daughter is a smart baby”.

Secondly note that together the pre-suppositions are sufficient, that is to say that together they deductively entail “my grand-daughter is a smart baby”.

Thirdly note that “my grand-daughter is a smart baby” acts as the conclusion of an argument with the three pre-suppositions as premises. This is not necessary. Say you tell me “my grand-daughter is a smart baby”. I do not pre-suppose that you have at least one female grand-child. I may reason from your statement to the belief that you have at least one female grandchild. I pre-suppose that your grand-daughter is a smart baby and conclude that you have at least one female grand-child.

Now, from the first note, we can see that “not pre-supposing X” does not entail “pre-supposing not-X”. You seem to think that an atheist necessarily pre-supposes that there is no God. This is simply rubbish; about as sensible as claiming a grandfather necessarily denies the existence of Led Zeppelin.

From the third we can see that we can start with the pre-supposition of the laws of logic. You may argue to them, we don't have to.

The second removes any support that your argument has for the proposition that either God exists or the laws of logic exist. You start off from the pre-suppositions that God exists and the laws of logic exist. That is sufficient to entail “God exists” and "the laws of logic exist" thus anything else is un-necessary and cannot count as a pre-supposition or a premise: they are not your reasons for accepting the existence of God and logic. “God exists” also fails to combine with other necessary pre-suppositions to entail “the laws of logic”. If God could create the laws of logic then God could decide not to create the laws of logic. In particular God could have decided to create different laws of logic from the ones that we have now. We cannot reason from “God” to any statement about logic. Thus “God” entails nothing about logic and cannot be your reason for accepting the laws of logic.

Your alternative argument is “It is proven by the impossibility of the contrary. No other worldview can account for the universal, abstract, invariant laws of logic.”

You have got “contrary” wrong. “If God did not exist then the laws of logic would not exist” negates to “the laws of logic exist and God does not”. It does not negate to “we can account for the universal, abstract, invariant laws of logic”. Write it out (use Stephen’s suggestion of truth tables), you can see that there are eight possible combinations of:1. God exists (true/false) and2. We can account for the laws of logic (true/false)3. The laws of logic existWe can have:1. God exists, we can account for the laws of logic, the laws of logic exist2. God exists, we can account for the laws of logic, the laws of logic do not exist3. God exists, we cannot account for the laws of logic, the laws of logic exist4. God exists, we cannot account for the laws of logic, the laws of logic do not exist5. God does not exist, we can account for the laws of logic, the laws of logic exist6. God does not exist, we can account for the laws of logic, the laws of logic do not exist7. God does not exist, we cannot account for the laws of logic, the laws of logic exist8. God does not exist, we cannot account for the laws of logic, the laws of logic do not exist

We can rule out “2” and “6” (we cannot account for the existence of things that do not exist). That still leaves us with six! You claim “1”, incorrectly because you cannot account for the laws of logic (as above). You also claim to establish “1” by denying “5”: an argument that depends upon the totally erroneous claim that “5” is the “contrary” of “1”.

Paul - yes I concur. Sye would win much respect and we could then spend more time on his own questions to us, rather than having to faf about explaining for the nth time why Sye's website "proof" is not, as it stands, a proof.

btw the dictionary defintion of presupposition is a bit confusing as it's Strawson, who makes a a distinction between presupposing and asserting when attacking Russell's theory of descriptions. Russell says that when I say "The Kinf of France is bald" I assert there is exact one K of F. That makes sentence come out as false. Strawson says I don't assert, but presuppose, there's exactly one K of F, which is why what I say is neither true nor false.

Another example - "Have you stopped beating your wife?" this does not assert, bt presupposes, you beat your wife. Which is why you can answer neither yes nor no!

For our purposes - and Sye may agree - a presupposition could be an unsupported/unargued for claim.

In any argument, the basic premises are all, in this sense, presupposed (though further argument might be furnished to support them, say).